Preparation Steps

• Heat the oven to 400°F (204°C). Line a standard 12-cup muffin pan with paper liners.
• In a medium bowl, whisk together the flour, cinnamon, baking soda, salt, and espresso powder. Scoop out 1 tablespoon of this dry mixture into a small bowl and set aside for the chocolate chips.
• Coarsely grate the zucchini with the skin on. Gather it in a clean kitchen towel and wring out as much liquid as you can. Measure 1 1/2 cups after squeezing and fluff with a fork.
• In a large mixing bowl, combine the sugar and orange zest. Rub them together with your fingertips until the sugar is fragrant and slightly damp. Whisk in the eggs for 30–45 seconds until lightly foamy and paler in color.
• Slowly whisk in the oil, then the sour cream and vanilla, until the mixture is smooth and cohesive.
• Add the dry ingredients to the bowl in two additions, folding gently with a spatula just until you no longer see dry streaks.
• Toss the chocolate chips with the reserved tablespoon of dry mix to lightly coat. Fold the zucchini and the coated chips into the batter until evenly distributed. Let the batter rest for 5–10 minutes to hydrate. Tip: If your zucchini was very dry, loosen the batter with 1–2 teaspoons of milk or water before portioning.
• Divide the batter among the liners, filling each nearly to the rim. For bakery-style tops, reserve a few chips to press onto the surface of each muffin.
• Bake for 5 minutes at 400°F, then (without opening the oven door) reduce the temperature to 350°F (177°C) and continue baking 11–13 minutes, until the tops are set and a toothpick comes out with a few moist crumbs.
• Cool in the pan for 5 minutes, then transfer muffins to a wire rack to cool for 15–20 minutes before serving.